| Abstract Scope |
Pneumatic droplet-on-demand liquid metal jetting (LMJ) provides a powder-free method of generating metal parts with a unique combination of advantages over other jetting methods: jetting feedstock of any conductivity, no moving parts contacting the molten feedstock, versatile switching between constant jetting and droplet-on-demand modes, and straightforward miniaturization for multi-nozzle jetting. However, pneumatic LMJ typically has momentum pulses that are too slow to match the capillary timescale at the nozzle, resulting in reduced jetting performance, coarser resolution, and consequently diminished part quality. We present our continued development of a fast pneumatic printhead and evaluate its performance in jetting water, tin, and bismuth droplets using a push-pull waveform. Results demonstrate improvements in resolution, jetting stability, droplet pinch-off speed, and droplet velocity while linking these enhancements in performance to underlying process physics. Prepared by LLNL under Contract DE-AC52-07NA27344. LLNL-ABS-2018960. |